Lawn-mower sharpener.



J, HINEMAN. LAWN MOWER SHAEPENER.

APPLICATION FILED I'EB.12. 1914.

1,103,584. Patented;Ju-1y 14,1914,

M66665: fi 77/1401."

JOHN HINEMAN, OF CEDAR RAPIDS, IOWA.

LAWN -MOWER SHARPENER.

Specification of Letters Patent.

Patented July 14, 1914.

Application filed February 12, 1914. Serial No. 818,268.

To all whom it may concern:

Be it known that I, JOHN HINEMAN, a citizen of the United States,residing at Cedar Rapids, in the county of Linn and State of Iowa, haveinvented certain new and useful Improvements in Lawn-Mower Sharpeners,of which the following is a specification.

This invention relates to devices for sharpening the rotary knives oflawn mowers; and the object of the invention is to produce a sharpeningdevice of simple construction adapted to be easily and quickly attachedto a lawn mower, and to sharpen the same by rotating the mower, as inmowing, except that the mower is drawn instead of being pushed.

The nature of the invention is fully set forth in the description andclaim following, reference being had to the accompanying drawing, inwhich Figure 1 is a cross-section of the sharpening device as applied toa mower. Fig. 2 is a rear view of the same detached.

Referring to the drawing, 1 denote the rotary cutter-head of a lawnmower, provided with curved blades 2. To the crossbar 3 of the mainframe is attached the ledger-blade 4, with which the rotary cuttercooperates. In Fig. 1 the handle 5 is shown depressed, merely forconvenience in drawing and illustrating the device, but it will beunderstood that in actual use the handle is turned up to the regularworking angle, but with the mower inverted, and is thus drawn along theground.

To a block'6, which may be of wood or metal, is attached, as by screws,a slab of suitable abrasive material, preferably carborundum, with astraight lower edge. This straight, grinding edge of the slab 7, as willbe seen, depends far enough below the block so as to be slightly lowerthan the cutting edge of the ledger-blade, the difference, in practice,being hardly appreciable, however, as the grinding is done without anychange in adjustment of the cutting apparatus, except the slightadjustment necessary after the grinding is finished.

Through the block passes a pair of hookbolts 8, provided with thumb-nuts9. The hooks of the bolts engage the flange 10 of the cross-bar 3, andhold this side of the block securely in position. In practice thisholding of the bar is not made perfectly rigid, however, since thegrinding slab should yield slightly in the act of grinding. This slightelasticity is secured by the interposition of a yielding materialpreferably sheets of rubber 11 between the block and the thumb-nuts. Itis preferred to mount a pair of metal strips 12 over the elastic shims11, as shown. Between these shims and the thumb-nuts are interposed theholders for the grinder side of the block, a pair of curved, andslightly flexible hooks 13, the hooked ends of which engage thecross-r0d 14 connecting the gear-cases 15 at opposite ends of the mower.It will be seen that a slight tightening of the thumb-screws will havethe effect of easing off the abrading slab, while a correspondingloosening of the nuts will allow it to go down a trifle, with increasedgrinding contact.

hen in position for grinding, which attachment is the work of but a fewmoments, the cutters are quickly and accurately ground by simply drawingthe mower over the ground. The grinder is as quickly detached, theslight adjustment is made in the pitch of the ledger-blade, and themower is ready for work with keen and smoothly cutting blades.

Having thus described my invention, I claim:

A grinder for lawn-mowers, comprising a straight-edged abrasive slab, aholder therefor adapted to rest on the ledger-blade of the mower,hook-bolts adapted to clamp said holder in position at one side, andcurved, slightly elastic hooks engaging said holder at one end, and atthe other end engaging the mower cross-rod.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN HINEMAN.

Witnesses WM. E. TREIOI-ILER, M. L. EBY.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

- Washington, D. G.

